The project will develop a portable microanalytical system based on nanoparticle labels/ immunochromatographic electrochemical biosensor (IEB) for on-site rapid detection and quantification of tobacco smoke exposure (TSE)-induced multiple biomarkers in biological matrices. The detection of TSEinduced biomarkers is based on the principle of immunochromatographic separation and nanoparticleenhanced bioelectrochemical detection. To improve the sensitivity of electrochemical detection in the immunochromatographic platform, apoferritin-templated metallic phosphate nanoparticle labels will be employed to amplify detection signals of those biomarkers. The first goal of this Project is to establish nanoparticle-based competitive electrochemical immunoassay for (a) cotinine as a marker of tobacco smoke exposure. The detection system will be tested and evaluated using human plasma and urine samples (Project 1) and mouse plasma, urine, and saliva (Project 2). Secondly, Project 3 will establish nanoparticlebased multiplexed electrochemical immunoassay for sequence specific nitrotyrosine, sequence - independent nitrotyrosine (identified by Project 1 and 2, and Core A and B) and the pleiotropic, non-specific marker, TNF-alpha. Finally, this Project will build a prototype Immunochromatographic/ Electrochemical Biosensor (IEB) device for on-site application. The device will provide for analysis of exposure (cotinine), selected markers of specific (nitrated proteins) and general markers of stress (e.g. TNF-alpha) in a single platform.